In recent years, as semiconductor integrated circuits have become progressively finer, projection lithography techniques using EUV light which has a wavelength of approximately 13 nm have been developed in order to increase the resolving power of optical systems, which is limited by the diffraction limit of light. Such EUV exposure apparatuses comprise a lens barrel which accommodates a projection optical system that projects the pattern on the original plate onto the sensitive substrate, an original plate stage which moves and positions the original plate, a sensitive substrate stage which moves and positions the sensitive substrate, and the like. These components such as stages are generally installed inside a vacuum chamber in order to prevent absorption of the EUV light by air. A vacuum pump that is used to generate a vacuum, and piping that is used to accommodate electrical cables, an exhaust pipe, and the like are connected to this vacuum chamber.
When the vacuum pump is operated so that a vacuum is generated inside the vacuum chamber, static and dynamic deformation occur in the vacuum chamber due to the effects of vibration of the pump itself and fluctuations in the atmospheric pressure. Consequently, such deformation of the vacuum chamber is transmitted to the components such as stages, and thus causes a deterioration in the exposure performance (stage synchronization precision, aberration, variation in performance values, and the like).
Meanwhile, in a high-vacuum environment, if the piping is made of a synthetic resin, gases that have a broad range of molecular weights are emitted. Accordingly, such synthetic resin piping is undesirable. Consequently, a material which has a low gas permeability and a relatively high rigidity must be used as the material of the piping. However, since piping consisting of a material that has a high rigidity has a large bending radius, the piping layout design inside the apparatus is restricted, so that it is difficult to realize desired apparatus specifications. Furthermore, if the piping has a high rigidity, the vibration of the vacuum pump and the like is easily transmitted to the apparatus units (stage system and optical system) via the piping, so that there is a danger that the exposure performance will also be caused to deteriorate by the effects of this vibration.